Chapter 8: Users and Groups

Exercise 8-1

The answer is given on p.154:

It is possible (but unusual) to have more than one record in the password file with the same user ID, thus permitting multiple login names for the same user ID. This allows multiple users to access the same resources (e.g., files) using different passwords. The different login names can be associated with different sets of group IDs.

Exercise 8-2

My solution is in my_getpwnam.c.

To use this solution:

1. Use make my_getpwnam to compile and link the code.
2. Use ./my_getpwnam postgres to execute this code.

The result should be similar to the following:

Login name (postgres) match
Password match
User ID (1001) match
Group ID (1001) match
User info (PostGres DB Owner,,,) match
Home directory (/home/postgres) match
Shell (/bin/bash) match